1. Field of the Invention
The present invention relates generally to an improved shaft seal system, and more particularly, to a dual seal system for a boat or other watercraft for creating a fluid tight seal between a rotatable shaft and a structure through which the shaft passes.
2. Description of the Related Art
Many designs for marine shaft seal systems have been designed in the past. None of them however, include a shaft seal system where a shaft seal may be replaced while the boat or watercraft is in a body of water, without removing it to dry dock.
Typical shaft seal systems only have one seal. Usually, water comes from the engine water pump to the shaft seal. The water circulates throughout channels or grooves in a bushing and exits through a tunnel of the boat to the body of water. With these types of shaft seal systems, water circulates to cool and lubricate the propeller shaft bushing. However, when the watercraft accelerates and attains a cruising speed, a vacuum is created in the tunnel. During high shaft rotation, the vacuum forces water to exit the bushing, not allowing the water to cool and lubricate when most needed.
If there is a seal failure, water immediately enters the boat. Additionally, when a shaft seal needs to be replaced with this type of shaft seal system, the watercraft needs to be removed from the body of water to a dry dock. This procedure is time consuming and expensive. The instant invention remedies this problem easily and efficiently.
Applicant believes that the closest reference corresponds to U.S. Pat. No. 6,039,320 issued to MacDonald for an xe2x80x9cAdjustable Seal For Propeller Drive Shaftxe2x80x9d. However, it differs from the present invention because MacDonald teaches an adjustable sealing device for sealing between rotatable drive shaft, such as a propeller drive shaft, and the aperture in a structure, such as the hull or bulkhead of a vessel, through which the shaft passes. The device is generally rigid and is comprised of an adapter ring, a slide ring, a diaphragm positioned between the adapter ring and the slide ring, a friction ring having one end positioned in the adapter ring and a seal surface engageable with the seal surface of a seal ring rotatable with the shaft, biasing means positioned between the slide ring and the friction ring for urging the seal surfaces together, and a spring cover acting as a seal redundant to the diaphragm.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.
A shaft seal system for watercrafts. The invention comprises two seals, one at each end of a cylindrical member with cooling and lubrication means within a camera. To cool and lubricate, water enters an entry port and circulates throughout the camera channels and watercraft shaft, which drives the watercraft propeller. Said water then exits an exit port.
The water to cool and lubricate the seals and bushing comes from the engine water pump. An entry port hose connects the engine water pump to the entry port of the bearing. Water circulates to both seals throughout the camera channels, and exits through the exit port on the other side of the bearing. Water that exits through the exit port flows through an exit port hose to an exhaust system.
This instant invention proposes increased cooling and lubrication regardless of watercraft speed, resulting in longer lasting seals and reduction of maintenance.
More specifically, the instant invention is a shaft seal system rotably mounted on a propeller shaft for a watercraft hull comprising a cylindrical member with first and second ends, said cylindrical member housing a first shaft seal. The first shaft seal is retained within said cylindrical member adjacent to said first end and the second end has a peripheral flange. A removable ring comprises a plurality of semi-rings cooperatively fastened to each other to house a second shaft seal within. The removable ring has cooperative dimensions to fastenly secure to the peripheral flange of the cylindrical member. The said second shaft seal may be replaced with a new shaft seal rotably mounted on said propeller shaft while the watercraft is in a body of water without the intrusion of water inside a hull.
Additionally, the shaft seal system further comprises means for cooling and lubricating said shaft seal system and said propeller shaft. The cooling and lubricating means comprise a bearing with third and fourth ends, housed within said cylindrical member at a first predetermined distance from said first end, extending a second predetermined distance towards said second end without reaching said second end. The bearing comprises a plurality of channels to allow water to circulate between said first and second shaft seals and around said propeller shaft. The bearing has an entry port to allow said water to flow in and an exit port to allow said water to flow out of said bearing. The water to cool and lubricate flows to said entry port from a water pump and to an exhaust system from said exit port.
To prevent water leakage between the cylindrical member and the removable ring, a seal such as an xe2x80x9cOxe2x80x9d ring, fits between said removable ring and said flange.
To secure the cylindrical member to a tunnel of a hull, or an extension from the hull, the cylindrical member is threaded a third predetermined distance from said first end towards said second end without reaching said second end, wherein a hose from said watercraft is clamped to said cylindrical member where threaded to secure said shaft seal system on said propeller shaft.
The second shaft seal may be replaced with a nylon flex, rubber, cloth, or similar pack when a new shaft seal is not available on the propeller shaft.
It is therefore one of the main objects of the present invention to provide a shaft seal system utilized on watercrafts, having dual seals, of which one of the seals may be replaced while the watercraft is in a body of water.
It is another object of the present invention to provide a shaft seal system having dual seals, of which one of the seals may be replaced without having to remove the watercraft to dry dock.
It is another object of the present invention to prevent water from entering a vessel and leaving the confines of the shaft seal system according to the invention.
It is another object of the present invention to provide a shaft seal system utilized on vessels having a propeller shaft extending from an inboard motor or gear box to an outboard propeller.
Another object of the invention is to provide means incorporated within, for cooling and lubricating, where water enters an entry port and circulates throughout camera channels within a cylindrical member and around a shaft which drives the watercraft propeller.
Another object of the invention is to provide a system for preventing water from entering a vessel having a shaft, which extends through the hull or bulkhead of the vessel.
A further object of the invention is to provide a fluid-sealing device for a vessel having a shaft, which runs through the hull or bulkhead of the vessel, which can be used with many different types of apparatus for receiving a shaft where it extends through the hull or bulkhead.
Another object of the present invention is to provide a device as described above to which adapters may be attached, each respective adapter adapting the device for mounting to a different hull aperture configuration.
Another object of the present invention is to provide a device as described above which includes a dual seal system.
Another object of the invention is to provide a water-seal apparatus for the shaft of a vessel which is safe in operation, durable and easy to make, uses known components and raw materials, and which furthermore is effective, efficient and reliable in operation.
It is yet another object of this invention to provide such a device that is inexpensive to manufacture and maintain while retaining its effectiveness.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.